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#1 (**permalink**) 04-11-2008, 06:52 AM

> > Since that costs, I guess I would make it optional and combine it
with
> > materialized views that are automatically used at runtime, and can
at
> > the same time answer other aggregates or aggregates for groups.
> > create materialized view xx_agg enable query rewrite as select
> > count(*), sum (col1) from xx [group by col2];
> >
>
> I wonder how many times you really need a count(*) w/o where clause.
> If I understand you correctly you are trying to optimize just this one
case?

I guess you have not read to the end. A materialized view with a group
by
as indicated in the example is able to answer all sorts of queries
with or without where clauses ( e.g. ... where col2 = 'x').

Andreas

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#2 (**permalink**) 04-11-2008, 06:52 AM

Zeugswetter Andreas DCP SD schrieb:
>>>Since that costs, I guess I would make it optional and combine it
>
> with
>
>>>materialized views that are automatically used at runtime, and can
>
> at
>
>>>the same time answer other aggregates or aggregates for groups.
>>>create materialized view xx_agg enable query rewrite as select
>>>count(*), sum (col1) from xx [group by col2];
>>>
>>
>>I wonder how many times you really need a count(*) w/o where clause.
>>If I understand you correctly you are trying to optimize just this one
>
> case?
>
> I guess you have not read to the end. A materialized view with a group
> by
> as indicated in the example is able to answer all sorts of queries
> with or without where clauses ( e.g. ... where col2 = 'x').

But wouldn't that mean I need a materialized view (does we have
that now or do I need to play the usual games with triggers?)
for every possible where condition?

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Re: Improving count(*)

**Re: Improving count(*)**